GAO Line Echo Canceller
by GAO Research & Consulting Ltd.

Software Overview

The Line Echo Canceller software cancels electrical echoes due to 2-to-4 wire conversion hybrids in 
telephone lines. The echo canceller is also designed for integration with other DSP software to 
enhance performance such as the DTMF Encoder/Decoder.

Features and Benefits

•	Implemented in the assembly
•	Double-talk detection

Processor and System Requirements

•	Devices supported: TMS320C3x, TMS320C5x, TMS320C54x
•	Algorithm category: Telecommunications
•	Required:
Function
Average MIPS
Data Memory
Program Memory
Canceller
6
500
750

Algorithm Verification

•	Tested against ITU G.165.

Availability

•	The software is available now and demonstration is available at GAO's offices in Toronto, Canada.

Company Background and Contact Information

GAO Research & Consulting Ltd. is an established international supplier of DSP algorithms, 
software, and systems for the telecommunications market. It provides a complete line of telephony, 
fax, and modem solutions. Its products have been widely reported by over 30 leading publications in 
the industry.
GAO currently employs about 20 DSP engineers. It was founded in 1991 and has been managed by Dr. 
Frank X.Y. Gao.
Contact:	Dr. Frank X.Y. GAO, CEO
		GAO Research & Consulting Ltd.
		55 Nugget Avenue, Unit 204
		Scarborough,  Toronto
			Ontario, Canada M1S 3L1
		(416) 292-0038
		Fax: (416) 292-2364
		e-mail: gao@io.org
		www: http://www.io.org/~gao